Solar light-induced photodegradation of chrysene in seawater in the presence of carbon-modified n-TiO2 nanoparticles

Photocatalytic degradation of chrysene in polluted seawater was successfully achieved under illumination of natural sunlight using carbon modified titanium oxide (C-TiO₂) nanoparticles. The morphological and structural characteristics of the as-synthesized nanoparticles were investigated by X-ray diffraction (XRD), UV–Vis spectra, scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared (FT-IR), and X-ray photoelectron spectroscopy (XPS). The characterization results confirmed the successful incorporation of carbon into C-TiO₂ nanoparticles. As a result of C-modification, a significant enhancement of the photocatalytic degradation efficiency was observed for C-TiO₂, compared with pure TiO₂. In order to optimize the operating parameters, the impacts of catalyst loading and pH on the photocatalytic degradation of chrysene were investigated. The best degradation rate was obtained at pH 3 and C-TiO₂ loading of 1.0 g L⁻¹. The photodegradation of chrysene in seawater by using C-TiO₂ was found to follow a pseudo first-order kinetics in terms of the Langmuir-Hinshelwood model.